METAIRIE, LA. – Saints strong safety Roman Harper has had quite a roller-coaster start to this season, picking up right where he left off last year.

He began with the high of a new four-year, $25 million contract in late July, with the Saints proving how much they value his abilities as a hard-hitting playmaker. Then he had a rough night in Week 1 at Green Bay, getting picked on a couple times in pass coverage by quarterback Aaron Rodgers in a shootout loss to the Packers.

Last week against the Chicago Bears, Harper was again involved in the costliest play of the game, when he was flagged 15 yards for a supposedly-illegal hit on Jay Cutler that kept alive the Bears’ only touchdown drive and gave them a 7-0 lead. But Harper went on to deliver several more big hits in the game, including two sacks of Cutler. He wound up winning NFC Defensive Player of the Week honors.

Then the league office called this week to let the Saints know his first-quarter hit was perfectly legal and no flag should’ve been thrown. Harper said the phone call was nice, but he wasn’t planning on changing his aggressive style regardless. Although the 6-1, 200-pounder remains inconsistent in pass coverage, the two-time Pro Bowler now leads all NFL safeties with 12 sacks since 2006 and ranks third among safeties with 12 forced fumbles.

Notes: The Saints’ defense has a lot of injury concerns heading into a tough matchup against Houston’s prolific offense this week. Linebackers Jonathan Vilma (knee) and Jonathan Casillas (foot), Harper (ankle) and cornerback Tracy Porter (calf) all missed Wednesday’s practice with injuries. The Saints remain optimistic that most of them will be back in practice Thursday. Porter appears to be the biggest question mark of the bunch. The Saints’ secondary did step up in Porter’s absence last week against Chicago, with starters Jabari Greer and Patrick Robinson holding up well in mostly man coverage. But this week they’ll be facing arguably the NFL’s best receiver in Andre Johnson.